This invention relates to novel insect killing compositions for the control of ectoparasites on animals and to methods for using the compositions. More particularly, the invention relates to the control of fleas on warm blooded animals such as dogs and cats, by application of an insecticidal composition, conveniently in the form of a shampoo, directly to the animal's body.
Various washes and shampoos have been proposed in the art for controlling fleas on cats and dogs. However, there have been several untoward effects caused by such products. These include allergic sensitivity reactions evidenced by the animal's skin and/or fur and difficulty in use, i.e. long "soak" times were required for lack of effectiveness of such products. More recently the use of pet collars, in which an insecticide gas generating composition is included, have been widely adopted. These types of products also suffer from certain disadvantages. For instance, pet collars composed of the insecticide dimethyl 2,2-dichlorovinyl phosphate, commonly known as DDVP, have been widely used for the purpose of controlling fleas on dogs and cats. DDVP has been reported in the literature to have an objectionable depressing effect on the plasma and red cell cholinesterase. This is particularly acute at high concentrations which are produced during the first few days after a collar has been applied to the neck of the animal. Additionally, local skin irritation has occurred at the site of the collar especially when the collar is first placed on the animal.
Despite these proposals and numerous commercially available products, a need exists in the art for providing a safe yet fully effective composition for treating animals such as dogs and cats for fleas.